1. Field
The disclosed embodiments relate to the protection of electronic communication systems and of the electronic units being connected through such communication system, respectively, in an aircraft against electromagnetic irradiation. In particular the disclosed embodiments relate to a method and an apparatus for determining the interfering field strength according to the preamble portion of claims 1 and 4, respectively.
2. Brief Description of Related Developments
The cabling of the communication system in vehicles and especially in aircrafts is usually disposed between the outer shell and the interior panelling of the vehicle. In this context the term cabling shall encompass all electrically conducting cables for transmitting electrical signals and for power supply. The outer shell of aircrafts is usually made up of metal and thus provides a good screening against irradiations to the outside. Correspondingly there is also only little induction in the cabling from outside.
For protecting the aircraft cabling against electromagnetic interferences from inside the aircraft e.g. by electromagnetic fields from passenger mobile phones many of the cables are shielded; single cables as well as entire cable bundles are enveloped in braided metal shields. Moreover cables are often twisted.
The screening of the cables however considerably contributes to the overall weight of the aircraft. By omitting the shielding a weight reduction of up to ca. 150 kg is achievable. On the other hand, in the above prior art this would cause a deterioration of the interference protection and incur detrimental effects on the performance of the electronic aircraft system by electromagnetic interferences, i.e. the performance of certain electronic components and of the communication system might be adversely affected.